Anorectal Abscess and Fistula — MCQs
A 5-month old child rushed into hospital with complaint of colicky pain, bilious vomiting and red current jelly like appearance of stools. On examination, there was a sausage shaped mass in the right lumbar region. Which of the following is the preferred modality that is used as both diagnostic and therapeutic?
A jeep driver presents with pain in the gluteal region along with swelling and pus discharge for the past 6 months. What is the most likely diagnosis?
Which of the following is a characteristic feature of Crohn's disease?
Most common site for anal fissure is
Causative organism for ANUG is:
What is the treatment of choice for anal carcinoma?
Hose pipe appearance of intestine is a feature of
Which of the following is the most serious complication of untreated urethral stricture?
A young male patient presents with complete rectal prolapse and no history of previous surgeries. The surgery of choice is:
During incision and drainage of ischiorectal abscess, which nerve is most likely to be injured?
Anorectal Abscess and Fistula Indian Medical PG Practice Questions and MCQs
Question 1: A 5-month old child rushed into hospital with complaint of colicky pain, bilious vomiting and red current jelly like appearance of stools. On examination, there was a sausage shaped mass in the right lumbar region. Which of the following is the preferred modality that is used as both diagnostic and therapeutic?
- A. Air enema (Correct Answer)
- B. MRI
- C. Anoscopy
- D. Barium enema
Explanation: ***Air enema*** - An **air enema** can be both diagnostic and therapeutic for **intussusception**, using air pressure to reduce the telescoping bowel segment. - The classic triad of **colicky pain, bilious vomiting, and red currant jelly stools** strongly suggests intussusception, and an air enema is often the first-line intervention. *MRI* - **MRI** is not typically used for the initial diagnosis or treatment of pediatric intussusception due to its long imaging times and need for sedation. - While it can provide detailed anatomical information, it is not a **therapeutic** modality for this condition. *Anoscopy* - **Anoscopy** is a procedure used to visualize the anal canal and distal rectum, primarily for conditions like hemorrhoids or anal fissures. - It is **not suitable** for diagnosing or treating intussusception, which involves a more proximal bowel obstruction. *Barium enema* - A **barium enema** can be diagnostic and therapeutic for intussusception, using barium solution to reduce the intussusception. - However, **air enema** is generally preferred due to a lower risk of perforation and easier interpretation of reduction, making it the more common choice.
Question 2: A jeep driver presents with pain in the gluteal region along with swelling and pus discharge for the past 6 months. What is the most likely diagnosis?
- A. Fistula in ano
- B. Fissure in ano
- C. Gluteal abscess
- D. Pilonidal sinus (Correct Answer)
Explanation: ***Pilonidal sinus*** - This is the classic presentation of **pilonidal sinus disease**, historically known as **"Jeep disease"** due to its high incidence in military personnel during WWII who sat for prolonged periods in jeeps - The **occupational clue "jeep driver"** is pathognomonic for pilonidal sinus, as prolonged sitting causes friction and pressure in the **sacrococcygeal/natal cleft region** - Presents with **chronic pain, swelling, and intermittent pus discharge** in the gluteal region, typically over weeks to months - Risk factors include: prolonged sitting, friction, deep natal cleft, obesity, and excessive body hair - The **chronic 6-month duration** with ongoing discharge is characteristic of pilonidal sinus with secondary infection, not an acute abscess *Gluteal abscess* - While this can cause pain, swelling, and pus discharge, it typically presents **acutely** (days to weeks, not 6 months) - Does not have the specific **occupational association with prolonged sitting** (jeep driver) - Would be expected to either resolve with drainage/antibiotics or progress to sepsis, not persist chronically for 6 months - Lacks the classic "Jeep disease" eponym *Fistula in ano* - This involves an abnormal tract between the **anal canal and perianal skin** - Discharge would be localized **perianally**, close to the anus, not in the broader gluteal/sacrococcygeal region - Does not have the jeep driver occupational association *Fissure in ano* - A **tear in the anal canal lining** causing severe pain during defecation with **bright red bleeding** - Does not present with swelling or chronic pus discharge - Pain is characteristically related to bowel movements, not constant
Question 3: Which of the following is a characteristic feature of Crohn's disease?
- A. Sinus & fistula (Correct Answer)
- B. Mesenteric lymphadenitis
- C. Continuous involvement
- D. Crypt abscesses
Explanation: ***Sinus & fistula*** - **Transmural inflammation**, a hallmark of Crohn's disease, can extend through the bowel wall, leading to the formation of **sinus tracts** and **fistulae** (abnormal connections between organs or to the skin). [1] - These complications include enteroenteric, enterovesical, and perianal fistulae, which are highly characteristic of Crohn's. [1] *Continuous involvement* - Crohn's disease is characterized by **skip lesions**, meaning there are healthy segments of bowel interspersed with diseased segments, not continuous involvement. [1] - **Ulcerative colitis** typically presents with continuous inflammation, starting from the rectum and extending proximally. [1] *Mesenteric lymphadenitis* - While mesenteric lymph nodes can be involved in Crohn's disease due to inflammation, **mesenteric lymphadenitis** is more commonly associated with infectious etiologies or other inflammatory conditions, and not a primary defining characteristic. - It refers to inflammation of lymph nodes in the mesentery, which can cause abdominal pain but does not specifically differentiate Crohn's from other conditions. *Crypt abscesses* - **Crypt abscesses** are a characteristic histological feature of **ulcerative colitis**, where neutrophils infiltrate the glandular crypts. [1] - While they can occasionally be seen in Crohn's, they are much more common and prominent in ulcerative colitis and are not a defining feature of Crohn's.
Question 4: Most common site for anal fissure is
- A. 3 O'clock
- B. 6 O'clock (Correct Answer)
- C. 2 O'clock
- D. 10 O'clock
Explanation: ***6 O'clock*** - The **posterior midline (6 o'clock position)** is the most common site for anal fissures, accounting for approximately **90% of all cases**. - This location is prone to tearing due to relatively **poor blood supply** and increased **mechanical stress** during defecation. - The posterior midline is the least supported part of the anal canal by the external anal sphincter. - **Note**: The **anterior midline (12 o'clock position)** is the second most common site, occurring in **10-25% of women** but rarely in men. *3 O'clock* - The **3 o'clock position (right lateral)** is an infrequent site for anal fissures. - Fissures in this location, especially if *lateral*, may suggest an underlying systemic disease such as **Crohn's disease**, **tuberculosis**, **HIV**, or **malignancy**. - Atypical fissures warrant thorough investigation. *2 O'clock* - The **2 o'clock position (anterior-lateral)** is not typically associated with anal fissures. - Similar to other atypical sites, a fissure here warrants investigation for secondary causes. - Consider inflammatory bowel disease or other pathological conditions. *10 O'clock* - The **10 o'clock position (left lateral)** is also a less common site for anal fissures compared to the posterior midline. - Fissures in lateral positions should raise suspicion for other conditions, such as **inflammatory bowel disease**, **tuberculosis**, **HIV**, or **malignancy**.
Question 5: Causative organism for ANUG is:
- A. Streptococcus sanguis
- B. Treponema pallidum and spirochetes
- C. Fusospirochetal complex (Correct Answer)
- D. Staphylococcus epidermidis
Explanation: ***Fusospirochetal complex*** - **Acute Necrotizing Ulcerative Gingivitis (ANUG)**, also known as Vincent's angina or trench mouth, is caused by a synergistic polymicrobial infection involving **Fusobacterium species** (particularly F. nucleatum) and **oral spirochetes** (Borrelia vincentii and Treponema species). - This fusospirochetal complex creates a destructive, ulcerative inflammation of the gingiva, presenting with **painful, bleeding gums, punched-out papillae, pseudomembrane formation**, and characteristic **fetid breath**. - The condition typically occurs in patients with **poor oral hygiene, stress, immunosuppression**, or **malnutrition**. *Streptococcus sanguis* - This bacterium is a common commensal of the oral cavity and plays a role in **dental plaque formation** and initial colonization of tooth surfaces. - While present in the mouth, it is **not the causative agent** for the necrotizing lesions characteristic of ANUG. *Treponema pallidum and spirochetes* - **Treponema pallidum** specifically causes **syphilis**, a sexually transmitted infection, not ANUG. - While **oral spirochetes** (other Treponema and Borrelia species) are indeed critical components of ANUG, they work synergistically with **Fusobacterium**, hence the term "fusospirochetal complex." - This option is partially correct but incomplete and includes T. pallidum which is incorrect. *Staphylococcus epidermidis* - **Staphylococcus epidermidis** is a skin commensal organism implicated in **nosocomial infections** and biofilm formation on medical devices. - It has **no role** in the pathogenesis of ANUG.
Question 6: What is the treatment of choice for anal carcinoma?
- A. Chemotherapy alone
- B. APR combined with radiotherapy
- C. Chemoradiation (Correct Answer)
- D. All of the options
Explanation: ***Chemoradiation*** - This combined modality is the **standard of care** for most anal carcinomas, achieving high cure rates while preserving sphincter function. - The combination of **chemotherapy** (e.g., 5-fluorouracil and mitomycin C) and **external beam radiation** works synergistically to destroy cancer cells. *Chemotherapy alone* - **Chemotherapy alone** is generally insufficient as a primary treatment for anal carcinoma. - It is often used in combination with radiation or for **metastatic disease**, but not as a monotherapy for curative intent in localized disease. *APR combined with radiotherapy* - **Abdominoperineal resection (APR)** combined with radiotherapy is typically reserved for **recurrent** or **persistent anal carcinoma** after failed chemoradiation, or for very advanced tumors. - APR is a highly morbid surgery leading to a **permanent colostomy**, and primary chemoradiation aims to avoid this outcome. *All of the options* - As **chemoradiation** is the preferred first-line treatment and other options are either inadequate or reserved for specific situations, stating "all of the options" is incorrect. - The treatment strategy for anal carcinoma involves a nuanced approach, prioritizing **organ preservation** with effective cancer control.
Question 7: Hose pipe appearance of intestine is a feature of
- A. Malabsorption syndrome
- B. Ulcerative colitis (Correct Answer)
- C. Crohn's disease
- D. Hirschsprung disease
Explanation: ***Crohns disease*** - The **hose pipe appearance** of the intestine on imaging is due to **transmural inflammation** and **strictures**, characteristic of Crohn's disease [1]. - This feature indicates a **narrowed lumen** due to fibrosis, often affecting the small intestine or colon [1]. *Malabsorption syndrome* - This condition is primarily associated with **nutrient absorption issues**, not structural changes in the intestine. - It typically presents with **diarrhea**, **weight loss**, and **malnutrition**, lacking the characteristic imaging findings. *Ulcerative colitis* - Usually presents with **continuous lesions** confined to the colonic mucosa, leading to ulcers and inflammation but not a **hose pipe appearance**. - Symptoms include **bloody diarrhea** and **abdominal pain**, distinctly different from Crohn's disease. *Hirsprung disease* - A congenital condition causing **intestinal obstruction** due to the absence of ganglion cells, leading to **dilated proximal bowel** rather than a hose pipe appearance. - Typically presents in infants with **severe constipation** and **abdominal distension**, unrelated to imaging features seen in Crohn's disease. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 366-367.
Question 8: Which of the following is the most serious complication of untreated urethral stricture?
- A. Periurethral abscess (Correct Answer)
- B. Urethral diverticulum
- C. Retention of urine
- D. All of these
Explanation: ***Periurethral abscess*** - An untreated urethral stricture can lead to urinary stasis and infection, which can then progress to a **periurethral abscess**. - A periurethral abscess is a serious localized collection of pus that can rupture internally or externally, causing severe pain, infection, and potentially necessitating complex surgical intervention. *Urethral diverticulum* - While urethral strictures can contribute to the formation of a **urethral diverticulum** due to increased pressure and obstruction, it is generally considered a less immediate and life-threatening complication compared to an abscess. - A diverticulum is an outpouching of the urethra, which can cause symptoms like dysuria, recurrent UTIs, and post-void dribbling, but does not typically pose the same acute infectious risk as an abscess. *Retention of urine* - **Urinary retention** is a common and significant symptom of a urethral stricture, as the narrowing blocks the flow of urine. - While uncomfortable and requiring intervention, acute urinary retention itself is usually manageable with catheterization and does not carry the same degree of tissue destruction and systemic infection risk as a periurethral abscess. *All of these* - While all listed options can be complications of an untreated urethral stricture, **periurethral abscess** represents the most serious due to its potential for severe infection, tissue destruction, and more complex management. - The question asks for the **most serious** complication, which points to the one with the highest morbidity and potential for systemic consequences.
Question 9: A young male patient presents with complete rectal prolapse and no history of previous surgeries. The surgery of choice is:
- A. Delorme's procedure
- B. Anterior resection
- C. Abdominal rectopexy (Correct Answer)
- D. Goodsall's procedure
Explanation: ***Abdominal rectopexy*** - **Abdominal rectopexy** is considered the surgery of choice for **complete rectal prolapse** in young, fit patients due to its superior long-term results in terms of recurrence rates. - This procedure involves addressing the prolapse via an abdominal approach, often by fixing the rectum to the sacrum, and may include sigmoid resection if there is a redundant colon. *Delorme's procedure* - This is a **perineal approach** that involves plication of the prolapsed rectal mucosa and muscle. - It is generally favored in **elderly** or **frail patients** due to its lower morbidity, but it has a higher recurrence rate compared to abdominal approaches. *Anterior resection* - **Anterior resection** is primarily a procedure for removing a diseased segment of the **left colon or rectum**, typically for cancer or diverticular disease. - While it may be combined with rectopexy if a redundant sigmoid colon is present, it is not the primary or sole treatment for rectal prolapse itself. *Goodsall's procedure* - **Goodsall's rule** is a principle used to predict the internal opening of an anal fistula based on the external opening's location, and **Goodsall's procedure** is not a named surgical technique for rectal prolapse. - This option appears to be a distractor, as there is no specific surgical procedure for rectal prolapse named after Goodsall.
Question 10: During incision and drainage of ischiorectal abscess, which nerve is most likely to be injured?
- A. Superior rectal nerve
- B. Inferior rectal nerve (Correct Answer)
- C. Superior gluteal nerve
- D. Inferior gluteal nerve
Explanation: ***Inferior rectal nerve*** - The **inferior rectal nerve** innervates the **external anal sphincter** and the skin around the anus, making it vulnerable during an incision and drainage of an **ischiorectal abscess** due to its anatomical proximity. - Injury to this nerve can lead to **fecal incontinence** or altered sensation in the perianal region. *Superior rectal nerve* - The **superior rectal nerve** is primarily involved in the innervation of the **rectum** and is not directly located in the area of an **ischiorectal abscess**. - This nerve supplies the smooth muscle of the rectum and is not anatomically vulnerable during incision and drainage of an abscess in the ischiorectal fossa. *Superior gluteal nerve* - The **superior gluteal nerve** supplies the **gluteus medius**, **gluteus minimus**, and **tensor fasciae latae muscles**, which are typically located much more superior and lateral to an **ischiorectal abscess**. - Damage to this nerve causes a characteristic **Trendelenburg gait**, which is unrelated to perianal surgery. *Inferior gluteal nerve* - The **inferior gluteal nerve** innervates the **gluteus maximus muscle**, which is also located more superiorly and laterally relative to the **ischiorectal fossa**. - Injury to this nerve would primarily affect hip extension and is not a common complication of **ischiorectal abscess** drainage.
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